1. Field of Art
This invention relates to a gun bolt having an oscillating head for a Gatling type gun.
2. Prior Art
This classic modern revolving battery gun, as shown by R. J. Gatling in U.S. Pat. No. 125,563, issued Apr. 9, 1872, held its gun bolts in their locked disposition by means of the main helical cam. Improvements on the mechanism for locking the gun bolt are shoen by H. McC. Otto in U.S. Pat. No. 2,849,921, issued Sept. 2, 1958, including a bolt carriage having slides which ride in spaced apart tracks in the rotor, and an oscillatible bolt head having interrupted threads. The radial projection of these threads is less than the radial projection of the slides, taken from the longitudinal axis of the gun bolt. The M61Al Vulcan 20 mm gun does not have an oscillatible bolt head, it utilizes a pivoting lock bolt. The 7.62 mm Minigun as exemplified in U.S. Pat. No. 3,595,128, issued to J. P. Hoyt, Jr., on July 27, 1971 has an oscillatible bolt head having a single locking lug which projects radially beyond the grooves which serve as slides. In U.S. Pat. No. 3,611,871 issued to R. G. Kirkpatrick on Oct. 12, 1971, the gun bolt has a head with a plurality of locking lugs on a body which reciprocates in a splined tube, and which tube is oscillated, to oscillate the head. The radial projection of the locking lugs is greater than the radius of the bore which supports the tube. In U.S. Pat. No. 3,766,821, issued to T. W. Cozzy et al on Oct. 23, 1973, the gun bolt has a fully rotating roller which provides the locking lugs. These lugs have a radial projection which is substantially equal to the radial projection of the body which serves as the slide. In the GAU-8/A 30 mm gun described in Technical Report ADTC-TR-73-66 dated September 1973, the gun bolt, shown in FIG. 14, has a rotatable head with locking lugs which are substantially equal in radial projection to the slides.
Generally speaking, it is conventional to make the overall width of the gun bolt no greater than was necessary to provide a projection of the slides into the tracks beyond the width of the ammunition. This minimized the mass of the gun bolt and, therefore, the power required to drive the gun. However, it limited the maximum angle of the main cam track, and, therefore, it limited the minimum diameter of the main cam track.